NEW YORK (CBSNewYork) — You probably assume that when you go under the knife, your surgeon is there for the entire procedure, but that may not always be the case.

So, what’s really going on in your operating room?

Moments before going under anesthesia, it’s comforting to think your surgeon will be right by your side the whole time.

But, as CBS2’s Maurice DuBois reported, as you drift off to sleep, the doctor may be drifting out of your room.

“Most people don’t even think to ask their surgeon, ‘Oh, while you’re operating on me, are you going to be there the entire time or will you be doing another operation?” said reporter Jonathan Saltzman.

It’s a practice called ‘simultaneous’ or ‘concurrent surgery.’

“Someone’s got to be there to begin the surgery. The specialist will come in at the right moment to do whatever needs to be done, and then they’re going to go down the hall and do the same thing,” Dr. Arthur Caplan explained.

In 2005, pitcher Bobby Jenks helped the Chicago White Sox break the team’s 88-year wait for a World Series win. He went on to play with the Boston Red Sox, and in 2015, told the Boston Globe this was exactly what happened to him.

“I had no idea that there was would have another surgery booked at the same time,” he said.

He maintains that his Major League career ended after a botched back operation was performed by a surgeon working in two different rooms.

“The more we looked into it, the more intriguing it got,” Saltzman said.

“It’s no different than a doctor who would see four patients in an hour, but now is booking eight patients in an hour,” he said.

Except with double, and sometimes even triple booked surgeries, there are a lot more risks — said Caplan, a bioethicist with the NYU School of Medicine.

“It’s not because the surgeon isn’t necessarily skilled, they are working with teams, and so if the anesthesia suddenly goes wrong, or a blood transfusion isn’t taking place right, they’re looking around to say, ‘Well, where’s the lead surgeon?” Caplan said.

“Now you have another patient, who’s now literally left with a resident or fellow who they’ve never met and otherwise would have never given informed consent,” Fronzuto explained.